from guidance import models, any_char_but

def test_single_char():
    model = models.Mock("<s>abc")
    assert str(model + '<s>' + any_char_but('a')) != "<s>a"
    assert str(model + '<s>' + any_char_but('!')) == "<s>a"

def test_multi_char():
    model = models.Mock(["<s>abc", "<s>bbc"])
    assert str(model + '<s>' + any_char_but('ab')) not in ("<s>a", "<s>b")
    assert str(model + '<s>' + any_char_but('a!')) == "<s>b"
    assert str(model + '<s>' + any_char_but('5b')) == "<s>a"